Interest on delayed tax payments accrues from the day after due date and is payable by the taxpayer. Section 50 requires payment of interest on tax unpaid beyond the prescribed period at a government notified rate within a statutory ceiling, calculated from the day after the tax became due. A proviso makes interest in respect of tax declared in late returns payable on the portion discharged from the electronic cash ledger, except where relevant assessment or adjudication proceedings have commenced. Wrongly availed and utilised input tax credit attracts interest at a higher notified rate, calculated as prescribed.